Run-time monitoring and on-line testing of middleware based communication services

With the present day's exponential growth of the (tele-)communications market, the explosion of the number of mobile communication customers, and the tremendous growth of the number of IP hosts, ensuring the reliability of communication services is one of the most challenging tasks in today's software engineering. This Thesis addresses this problem by providing a new method for increasing confidence in the implementation of communication services. We developed an approach for monitoring and testing communications services that are built on top of a middleware. Specifically, we show how to monitor a communication service and how to use the monitored information to test at runtime whether the behavior of the service conforms to constraints. The constraints are extracted from the requirements, expressed using a formal method. The approach advocated in this Thesis consists in combining the power of formal methods, which have reached a high degree of maturity in the academic domain, with a testing methodology, that fit the industrial needs, in order to test the implementation of a communication service. The developer can thus focus on the testing rather then on how the testing is performed. To solve this problem (1) we designed a monitoring mechanism that is able to observe at run-time, the events occuring in the system under scrutiny, (2) designed a testing mechanism that checks at runtime if properties expressed using Temporal Logic, are violated by the execution of the application, (3) implemented a prototype tool, MOTEL (MOnitoring and TEsting tooL). With our approach the tester need only to specify the properties. The other steps involved in the testing processes are performed automatically. According to the content of the properties the instrumentation is added in the system to be tested. This instrumentation reports a consistent order of the events occurring to a central Observer. Within this Observer, the properties, which are independent of the implementation language, are translated into deterministic automata. At run-time these automata are used, according to the events reported by the instrumentation to the Observer, to check if the properties are violated. Thus, our monitoring and testing mechanism fits well in the development process because it does not add noticeable new steps for the developer. In this thesis we put together many concepts and solutions from various domains (distributed systems, middleware, object-oriented development, CORBA, communication services, formal method, Temporal Logic, automata theory, monitoring, testing). By enhancing, developing and combining, and integrating them together, we reached a high level of integration that provides a new, powerful and useful functionality to test the implementation of communication services. We believe that there is not a more valuable argument for the application and practical relevance of our approach in the industry, than the introduction and use of our method and tool in and by the industry. Our partner, Alcatel, is currently integrating MOTEL in the distributed platform PERCO

Experimental demonstration of ray-rotation sheets

We have built microstructured sheets that rotate, on transmission, the direction of light rays by an arbitrary, but fixed, angle around the sheet normal. These ray-rotation sheets comprise two pairs of confocal lenticular arrays. In addition to rotating the direction of transmitted light rays, our sheets also offset ray position sideways on the scale of the diameter of the lenticules. If this ray offset is sufficiently small so that it cannot be resolved, our ray-rotation sheets appear to perform generalized refraction

Correlating twitter language with community-level health outcomes

We study how language on social media is linked to diseases such as atherosclerotic heart disease (AHD), diabetes and various types of cancer. Our proposed model leverages state-of-the-art sentence embeddings, followed by a regression model and clustering, without the need of additional labelled data. It allows to predict community-level medical outcomes from language, and thereby potentially translate these to the individual level. The method is applicable to a wide range of target variables and allows us to discover known and potentially novel correlations of medical outcomes with life-style aspects and other socioeconomic risk factors

Space and time multiplexing for field curvature correction in miniature imaging systems

The correction of field curvature by space or time multiplexing enables the design of a very simple imaging system for mobile device. Here, the optical design is presented and methods to correct the field curvature are discussed. This imaging system can be fabricated with wafer-level processes enabling large-scale and low cost productio

Role Enhancement of ZnO nanoparticles and ZnO/Ag composite for Medical Applications

ZnO nanoparticles assisted with ethanol and 2propanol as capping agent investigated the medical activities of ZnO nanoparticles and ZnO/Ag composite. ZnO nanoparticles were prepared using zinc acetate and silver nitrate as a source of zinc and silver. ZnO/Ag composite also prepared and studied the medical activities. XRD pattern indicates that the structure of ZnO was hexagonal wurtzite with average size 5 nm according to Scherre's formula. The optical band gap of ZnO nanoparticle showed very sensitive for using different capping agent as shown in UV-VIS spectra and also showed blue shift in wavelength corresponding to capping agent. Finally, the antibacterial properties of ZnO and ZnO/Ag composite against Gram-negative and Gram-positive bacteria have been demonstrated using well diffusion method and indentify their antibacterial effects compared with organic antibacterial agents. Keywords: ZnO nanoparticles, ZnO/Ag composite, antibacterial

A method to ease creation of telecommunications services based on a Generic Component Model

This paper proposes a method to ease the creation of -distributed- telecommunications services. The method is based on a generic component model which is a common software architecture applicable to the design of every component of a telecommunications service. The concepts, architecture and specification of the Generic Component Model are presented. The method based on the Generic Component Model is then applied to the design of a Connection Management Service on top of an ATM communication platform Keywords: TINA, Service Specification, Design and Management

Testing Temporal Logic Properties in Distributed Systems

The concept of event-based behavioral abstraction (EBBA) is shown to facilitate the Design For Testability (DFT) if the set of events is well-chosen. We provide a predefined set of events which, together with linear-time temporal logic, can be used for expressing behavioral properties in object-oriented distributed systems. This allows automizing several steps in the testing process: instrumenting the source code, constructing test-oracles and generating an observer. Taking an industrial example as basis, we discuss how our proposal can be integrated into the software design- and testing process